Effects of sulfoxide and sulfone sidechain–backbone hydrogen bonding on local conformations in peptide models

Abstract

We examine peptide model systems designed to probe short-range N–H⋯OS sidechain–backbone hydrogen bonding involving amino acid residues with sidechain sulfoxide or sulfone functional groups and its effects on local conformations. A strong 7-membered ring hydrogen bond of this type accompanies an intra-residue N–H⋯OC interaction and stabilizes an extended backbone conformation in preference to classical folded structures.